The Framing Effect

Imagine that a disease is expected to kill 600 people, and you must choose between two programs. With Program A, 200 people will be saved. With Program B, there is a one-third chance that all 600 will be saved and a two-thirds chance that no one will be saved. In a famous 1981 study, Amos Tversky and Daniel Kahneman gave this choice to a group of students. Most chose Program A, the certain option.

Another group received the same situation, described differently. [A] With Program C, 400 people will die. [B] With Program D, there is a one-third chance that nobody will die and a two-thirds chance that all 600 will die. [C] This time, most students chose Program D, the risky option. [D] Yet Programs A and C are identical, and so are Programs B and D. The only difference is whether the results are described in terms of lives saved or lives lost.

This tendency, known as the framing effect, shows that people's choices can depend on how information is presented, not only on the information itself. This can have real consequences. For example, patients are more likely to agree to an operation when they are told it has a 90 percent survival rate than when they are told it has a 10 percent death rate. For this reason, some experts recommend that doctors present the numbers in both ways.